Background: The aim of the publication is to show differences among patients with the first detected episode of atrial fibrillation (AF), paroxysmal, and persistent AF patients, for whom cardioversion was planned in the hospital setting in Poland.

Methods: We present an analysis of the Polish cohort of the multicenter, multinational RHYTHM-AF registry. Consecutive patients in the hospital setting, aged ≥ 18 years, with documented AF at the time of enrollment, and for whom cardioversion of AF is one of the planned therapeutic options were recruited. Follow-up data was collected 60 days after enrollment.

Results: Five-hundred-and-one patients were recruited, 483 with a defined AF type: 88 — first detected, 191 paroxysmal, and 204 persistent AF. CHA₂DS₂VASc scores were not significantly different between the groups, while treatment with vitamin K antagonists (VKA) was significantly lower in paroxysmal AF group than in persistent AF patients. Primary electrical cardioversion was most commonly performed in patients with persistent AF (90.4%), while primary pharmacological cardioversion — in the first detected AF (80.0%) and paroxysmal AF patients (76.7%). During 2 months of follow-up, the rate of rehospitalization and complications was comparable among the groups.

Conclusions: Despite their comparable CHA₂DS₂VASc scores, patients with persistent AF were more frequently treated with VKA antagonists than other groups. Recurrence of AF within 2 months after restoring sinus rhythm was present in about 25% of the patients, and the rate of complications was not different among the three groups.